Comparison between cold-stored platelets treated with riboflavin and UV light versus untreated cold-stored platelets

Riboflavin and UV light-based pathogen reduction technology (PRT) and cold-stored platelets (CSP) have a significant impact on platelet (PLT) function. The aim of this study is to determine whether the use of both methods is beneficial.

Twenty buffy coat (BC) PLT concentrates were grouped into 10 type-matched pairs, which were pooled and split into 10 non-PRT-treated PLTs and 10 PRT-treated PLTs, diluted in platelet additive solution (PAS-E) and leukoreduced. Both groups were cold-stored at 2-6ºC without agitation for 14 days (non-PRT CSP and PRT CSP). Hemostatic function and metabolic parameters were monitored on day 1 pre-refrigeration and on days 3, 7 and 14 of cold storage.

No swirling and no aggregates were observed at any time in either group after cold storage for 14 days. PRT CSP were less metabolically active (with better pH, lower lactate, lower pCO₂ and higher pO₂) than non-PRT CSP (p<0.001) after 14 days of cold storage. PRT CSP and non-PRT CSP resulted in faster clot formation over storage (p<0.001). Clot strength was reduced under optimal levels on day 14 in the PRT CSP (p<0.001).

The enhanced hemostatic PLT function achieved by CSP, i.e., faster clot formation, is also maintained by riboflavin and UV light treatment. The combination of riboflavin and UV light-based PRT and CSP has the added benefit of reducing platelet metabolism, which may have a positive effect on PLT viability. Further research is required to assess whether the in vitro benefits of combining PRT and CSP are confirmed in clinical trials.